4,706 research outputs found
Shannon entropy and particle decays
We deploy Shannon's information entropy to the distribution of branching
fractions in a particle decay. This serves to quantify how important a given
new reported decay channel is, from the point of view of the information that
it adds to the already known ones. Because the entropy is additive, one can
subdivide the set of channels and discuss, for example, how much information
the discovery of a new decay branching would add; or subdivide the decay
distribution down to the level of individual quantum states (which can be
quickly counted by the phase space). We illustrate the concept with some
examples of experimentally known particle decay distributions.Comment: 12 pages, 18 plots; to appear in Nuclear Physics
Overall evaluation of Skylab imagery for mapping of Latin America
The author has identified the following significant results. Skylab imagery is both desired and needed by the Latin American catographic agencies. The imagery is cost beneficial for the production of new mapping and maintenance of existing maps at national topographic series scales. If this information was available on a near time routine coverage basis, it would provide an excellent additional data base to the Latin American cartographic community, specifically Argentina, Bolivia, Chile, Colombia, Dominican Republic, Guatemala, Paraguay, and Venezuela
Ionized gas kinematics of galaxies in the CALIFA survey I: Velocity fields, kinematic parameters of the dominant component, and presence of kinematically distinct gaseous systems
This work provides an overall characterization of the kinematic behavior of
the ionized gas of the galaxies included in the Calar Alto Legacy Integral
field Area (CALIFA), offering kinematic clues to potential users of this survey
for including kinematical criteria for specific studies. From the first 200
galaxies observed by CALIFA, we present the 2D kinematic view of the 177
galaxies satisfying a gas detection threshold. After removing the stellar
contribution, we used the cross-correlation technique to obtain the radial
velocity of the dominant gaseous component. The main kinematic parameters were
directly derived from the radial velocities with no assumptions on the internal
motions. Evidence of the presence of several gaseous components with different
kinematics were detected by using [OIII] profiles. Most objects in the sample
show regular velocity fields, although the ionized-gas kinematics are rarely
consistent with simple coplanar circular motions. 35% of the objects present
evidence of a displacement between the photometric and kinematic centers larger
than the original spaxel radii. Only 17% of the objects in the sample exhibit
kinematic lopsidedness when comparing receding and approaching sides of the
velocity fields, but most of them are interacting galaxies exhibiting nuclear
activity. Early-type galaxies in the sample present clear photometric-kinematic
misaligments. There is evidence of asymmetries in the emission line profiles
suggesting the presence of kinematically distinct gaseous components at
different distances from the nucleus. This work constitutes the first
determination of the ionized gas kinematics of the galaxies observed in the
CALIFA survey. The derived velocity fields, the reported kinematic
peculiarities and the identification of the presence of several gaseous
components might be used as additional criteria for selecting galaxies for
specific studies.Comment: 38 pages, 16 figures, 4 tables. Paper accepted for publication in A&
Insights into the degradation capacities of Amycolatopsis tucumanensis DSM 45259 guided by microarray data
The analysis of catabolic capacities of microorganisms is currently often achieved by cultivation approaches and by the analysis of genomic or metagenomic datasets. Recently, a microarray system designed from curated key aromatic catabolic gene families and key alkane degradation genes was designed. The collection of genes in the microarray can be exploited to indicate whether a given microbe or microbial community is likely to be functionally connected with certain degradative phenotypes, without previous knowledge of genome data. Herein, this microarray was applied to capture new insights into the catabolic capacities of copper-resistant actinomycete Amycolatopsis tucumanensis DSM 45259. The array data support the presumptive ability of the DSM 45259 strain to utilize single alkanes (n-decane and n-tetradecane) and aromatics such as benzoate, phthalate and phenol as sole carbon sources, which was experimentally validated by cultivation and mass spectrometry. Interestingly, while in strain DSM 45259 alkB gene encoding an alkane hydroxylase is most likely highly similar to that found in other actinomycetes, the genes encoding benzoate 1,2-dioxygenase, phthalate 4,5-dioxygenase and phenol hydroxylase were homologous to proteobacterial genes. This suggests that strain DSM 45259 contains catabolic genes distantly related to those found in other actinomycetes. Together, this study not only provided new insight into the catabolic abilities of strain DSM 45259, but also suggests that this strain contains genes uncommon within actinomycetes.Fil: Bourguignon, Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Planta Piloto de Procesos Industriales Microbiologicos; ArgentinaFil: Bargiela, Rafael. Consejo Superior de Investigaciones Científicas; EspañaFil: Rojo, David. Centro de Metabolómica y Bioanálisis; EspañaFil: Chernikova, Tatyana N.. Bangor University; Reino UnidoFil: de Rodas, Sara A. López. Universidad Complutense de Madrid; EspañaFil: García-Cantalejo, Jesús. Universidad Complutense de Madrid; EspañaFil: Näther, Daniela J.. Goethe Universitat Frankfurt; AlemaniaFil: Golyshin, Peter N.. Bangor University; Reino UnidoFil: Barbas, Coral. Centro de Metabolómica y Bioanálisis; EspañaFil: Ferrero, Marcela Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Planta Piloto de Procesos Industriales Microbiologicos; ArgentinaFil: Ferrer, Manuel. Consejo Superior de Investigaciones Científicas; Españ
Albino T-DNA tomato mutant reveals a key function of 1-deoxy-D-xylulose-5-phosphate synthase (DXS1) in plant development and survival
[EN] Photosynthetic activity is indispensable for plant growth and survival and it depends on the synthesis of plastidial isoprenoids as chlorophylls and carotenoids. In the non-mevalonate pathway (MEP), the 1-deoxy-D-xylulose-5-phosphate synthase 1 (DXS1) enzyme has been postulated to catalyze the ratelimiting step in the formation of plastidial isoprenoids. In tomato, the function of DXS1 has only been studied in fruits, and hence its functional relevance during plant development remains unknown. Here we report the characterization of the wls-2297 tomato mutant, whose severe deficiency in chlorophylls and carotenoids promotes an albino phenotype. Additionally, growth of mutant seedlings was arrested without developing vegetative organs, which resulted in premature lethality. Gene cloning and silencing experiments revealed that the phenotype of wls-2297 mutant was caused by 38.6 kb-deletion promoted by a single T-DNA insertion affecting the DXS1 gene. This was corroborated by in vivo and molecular complementation assays, which allowed the rescue of mutant phenotype. Further characterization of tomato plants overexpressing DXS1 and comparative expression analysis indicate that DXS1 may play other important roles besides to that proposed during fruit carotenoid biosynthesis. Taken together, these results demonstrate that DXS1 is essentially required for the development and survival of tomato plants.This work was supported by research grants from the Spanish Ministry of Economy and Competitiveness and the UE-European Regional Development Fund (AGL2015-64991-C3-1-R, and AGL2015-64991-C3-3-R), and Junta de Andalucia (P12-AGR-1482). PhD fellowship to M.G.-A. was funded by the FPU Programme of the Spanish Ministry of Science and Innovation. The authors thank research facilities provided by the Campus de Excelencia Internacional Agroalimentario (CeiA3).Garcia-Alcazar, M.; Giménez Caminero, ME.; Pineda Chaza, BJ.; Capel, C.; García Sogo, B.; Sánchez Martín-Sauceda, S.; Yuste-Lisbona, FJ.... (2017). Albino T-DNA tomato mutant reveals a key function of 1-deoxy-D-xylulose-5-phosphate synthase (DXS1) in plant development and survival. Scientific Reports. 7:1-12. https://doi.org/10.1038/srep45333112
Deciphering the role of histone modifications in uterine leiomyoma: acetylation of H3K27 regulates the expression of genes involved in proliferation, cell signaling, cell transport, angiogenesis and extracellular matrix formation
Uterine leiomyoma (UL) is a benign tumor arising from myometrium (MM) with a high prevalence and unclear pathology. Histone modifications are altered in tumors, particularly via histone acetylation which is correlated with gene activation. To identify if the acetylation of H3K27 is involved in UL pathogenesis and if its reversion may be a therapeutic option, we performed a prospective study integrating RNA-seq (n = 48) and CHIP-seq for H3K27ac (n = 19) in UL vs MM tissue, together with qRT-PCR of SAHA-treated UL cells (n = 10). CHIP-seq showed lower levels of H3K27ac in UL versus MM (p-value < 2.2 × 10−16). From 922 DEGs found in UL vs. MM (FDR < 0.01), 482 presented H3K27ac. A differential acetylation (FDR < 0.05) was discovered in 82 of these genes (29 hyperacetylated/upregulated, 53 hypoacetylated/downregulated). Hyperacetylation/upregulation of oncogenes (NDP,HOXA13,COL24A1,IGFL3) and hypoacetylation/downregulation of tumor suppressor genes (CD40,GIMAP8,IL15,GPX3,DPT) altered the immune system, the metabolism, TGFβ3 and the Wnt/β-catenin pathway. Functional enrichment analysis revealed deregulation of proliferation, cell signaling, transport, angiogenesis and extracellular matrix. Inhibition of histone deacetylases by SAHA increased expression of hypoacetylated/downregulated genes in UL cells (p < 0.05). Conclusively, H3K27ac regulates genes involved in UL onset and maintenance. Histone deacetylation reversion upregulates the expression of tumor suppressor genes in UL cells, suggesting targeting histone modifications as a therapeutic approach for UL
Transition from Fireball to Poynting-flux-dominated Outflow in Three-Episode GRB 160625B
The ejecta composition is an open question in gamma-ray bursts (GRB) physics.
Some GRBs possess a quasi-thermal spectral component in the time-resolved
spectral analysis, suggesting a hot fireball origin. Others show a featureless
non-thermal spectrum known as the "Band" function, consistent with a
synchrotron radiation origin and suggesting that the jet is
Poynting-flux-dominated at the central engine and likely in the emission region
as well. There are also bursts showing a sub-dominant thermal component and a
dominant synchrotron component suggesting a likely hybrid jet composition. Here
we report an extraordinarily bright GRB 160625B, simultaneously observed in
gamma-rays and optical wavelengths, whose prompt emission consists of three
isolated episodes separated by long quiescent intervals, with the durations of
each "sub-burst" being 0.8 s, 35 s, and 212 s, respectively. Its high
brightness (with isotropic peak luminosity L
erg/s) allows us to conduct detailed time-resolved spectral analysis in each
episode, from precursor to main burst and to extended emission. The spectral
properties of the first two sub-bursts are distinctly different, allowing us to
observe the transition from thermal to non-thermal radiation between
well-separated emission episodes within a single GRB. Such a transition is a
clear indication of the change of jet composition from a fireball to a
Poynting-flux-dominated jet.Comment: Revised version reflecting the referees' comments. 27 pages, 11
figures, 5 tables. The final edited version will appear in Nature Astronom
Primordial non-Gaussianity with Angular correlation function: Integral constraint and validation for DES
Local primordial non-Gaussianity (PNG) is a promising observable of the
underlying physics of inflation, characterised by . We
present the methodology to measure from the Dark Energy
Survey (DES) data using the 2-point angular correlation function (ACF) with
scale-dependent bias. One of the focuses of the work is the integral
constraint. This condition appears when estimating the mean number density of
galaxies from the data and is key in obtaining unbiased
constraints. The methods are analysed for two types of simulations:
GOLIAT-PNG N-body small area simulations with equal to -100 and
100, and 1952 Gaussian ICE-COLA mocks with that follow the DES
angular and redshift distribution. We use the ensemble of GOLIAT-PNG mocks to
show the importance of the integral constraint when measuring PNG, where we
recover the fiducial values of within the when including
the integral constraint. In contrast, we found a bias of when not including it. For a DES-like scenario, we forecast a bias of
, equivalent to , when not using the IC
for a fiducial value of . We use the ICE-COLA mocks to validate
our analysis in a realistic DES-like setup finding it robust to different
analysis choices: best-fit estimator, the effect of IC, BAO damping,
covariance, and scale choices. We forecast a measurement of within
when using the DES-Y3 BAO sample, with the ACF in the
range.Comment: Version after MNRAS reviewer comments. Improved discussion in Section
7. 16 pages, 11 figure
Measurement of inclusive D*+- and associated dijet cross sections in photoproduction at HERA
Inclusive photoproduction of D*+- mesons has been measured for photon-proton
centre-of-mass energies in the range 130 < W < 280 GeV and a photon virtuality
Q^2 < 1 GeV^2. The data sample used corresponds to an integrated luminosity of
37 pb^-1. Total and differential cross sections as functions of the D*
transverse momentum and pseudorapidity are presented in restricted kinematical
regions and the data are compared with next-to-leading order (NLO) perturbative
QCD calculations using the "massive charm" and "massless charm" schemes. The
measured cross sections are generally above the NLO calculations, in particular
in the forward (proton) direction. The large data sample also allows the study
of dijet production associated with charm. A significant resolved as well as a
direct photon component contribute to the cross section. Leading order QCD
Monte Carlo calculations indicate that the resolved contribution arises from a
significant charm component in the photon. A massive charm NLO parton level
calculation yields lower cross sections compared to the measured results in a
kinematic region where the resolved photon contribution is significant.Comment: 32 pages including 6 figure
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